There is only one game left to be played before the MLB league championship series matchups are set.

It will take place on Thursday, Oct. 10, (9 p.m. ET, TBS) in Game 5 of the ALDS between the host Oakland A's and Detroit Tigers.

Awaiting the winner will be the Boston Red Sox, who beat the Tampa Bay Rays in four games in the other ALDS matchup.

In the National League, the Los Angeles Dodgers topped the Atlanta Braves in four games and will hit the road to meet St. Louis after the Cardinals eliminated the Pittsburgh Pirates in their Game 5 on Wednesday.

Let's take a look at the entire playoff schedule and a key player for each team's success in the remaining games.

Gray will have the biggest start of his young career on Thursday when he pitches in a do-or-die situation in Game 5 of the ALDS against Justin Verlander of the Detroit Tigers. Gray has already proven he can dominate the Tigers after throwing eight innings of scoreless ball in Game 2.

Not only is Gray vital to the A's advancing, but he also gives Oakland a deadly 1-2 punch behind ace Bartolo Colon. In fact, Gray has looked like an ace as well after going 5-3 with a 2.67 ERA during the regular season and he has looked the best of all the pitchers in the A's rotation in the ALDS.

Pitching is everything in the postseason. Having Gray playing at a high level gives the A's a great chance at success in October.

Detroit Tigers: Victor Martinez, Designated Hitter

Normally, you would choose either Prince Fielder or Miguel Cabrera as the key player for the Tigers on offense, but it's Martinez who takes the spotlight at the moment. Considering that both Cabrera and Fielder have combined for just one RBI in the ALDS and that Cabrera is playing hurt, Martinez's offense is sorely needed if Detroit hopes to advance.

Martinez has knocked in two runs in October, to tie him for second on the Tigers, and he's 6-for-16 overall with a .375 average. If Fielder and Cabrera continue to struggle, the offense must come from someplace and Martinez has the best bat for the Tigers to give shortstop Jhonny Peralta some support.

St. Louis Cardinals: Joe Kelly, Starting Pitcher

Charles LeClaire-USA TODAY Sports

Both Michael Wacha and Adam Wainwright took care of business in the ALDS, combining for all three of the Cardinals' wins to eliminate the Pittsburgh Pirates. However, St. Louis will need contributions from more than just its two starting pitchers and that's where Kelly comes into the equation.

Kelly was only able to last 5.1 innings in his lone start in the ALDS, as he allowed two runs on five hits with four walks. Still, that was better than Lance Lynn's awful performance in Game 2, which effectively pushed Kelly to No. 3 in the Cards' rotation.

Kelly was 10-2 with a 2.18 ERA in his last 15 outings after joining the rotation in early July. Numbers like that in October will give the Cards three top-flight starting pitchers and make them nearly impossible to beat.

Los Angeles Dodgers: Brian Wilson, Relief Pitcher

Harry How/Getty Images

Shortening games in the playoffs are key to any team's success and if the Los Angeles Dodgers can get the most out of reliever Brian Wilson, they have an opportunity to make games just seven innings long.

Wilson was stellar in 18 games for Los Angeles during the regular season. Wilson sported a 0.66 ERA in 13.2 innings and has yet to allow a run in three innings of work in October. If he can keep that up, Wilson and closer Kenley Jansen will give the Dodgers a surefire knockout punch once they maintain a lead late in games.

Boston Red Sox: Clay Buchholz, Starting Pitcher

Brian Blanco/Getty Images

Other than Jon Lester, Clay Buchholz was the only Boston Red Sox pitcher to notch a quality start this postseason, although it was a shaky one. as Buchholz allowed three runs on seven hits in six innings. It was a far cry from Buchholz in the regular season where he was 12-1 with a 1.74 ERA.

That's the version of Buchholz that the Sox need in the playoffs. He's the clear No. 2 starter in Boston's rotation. With John Lackey struggling and Jake Peavy having a lackluster postseason history, Buchholz must step up his game in order to give Boston enough depth in the starting rotation to win.